1987 Ranger 2.9l occasional high idle and jerking at highway speeds

[BasterizedRanger]

Yes, i know the first thing to do is run the codes but i dont have an obd1 reader available just yet. My ranger has an occasional high idle (1500-2000 rpm). Also when driving if i throw it in neutral it'll do it as well. Along with a check engine light that comes on and off every 10-45 seconds. When the light turns on and off, the truck jerks. Accelerating does great, no issues. I suspect its my throttle body as i have 1.16v on my TPS with throttle body closed, but i still have a 1/8" gap between throttle plate and screw like it could come back more but bound up. What are your giys thoughts?

 

[CMDRyzin]

Shouldn't need a obd1 "reader" although they do sell them on Amazon you can just as easily do without.

Get a paperclip and make a jumper wire to put your ecm into test mode. Here is a picture of what you should do.

Turn the key on but engine off and wait for the codes. Try googling eec 4 test and several videos will pop up explaining the process.

Just remember that our older trucks have a two digit flash code and the new ones are 3 digit.

Also you have a key on engine running test and a key on engine off test. Each one gives you separate codes.

Personally I use my phone to record the flashes on my dash. After I'm done I sit on the couch and research what I recorded, sometimes it takes awhile.

 

[rusty ol ranger]

Spend the 30 bucks on a reader. It makes things much simpler.

I would suspect the TPS if its above voltage at idle position

https://www.amazon.com/INNOVA-3145-Ford-Digital-Reader/dp/B000EW0KHW/?tag=959media-20

Same price at autozone if you want it now